1. Field of the Invention
The present invention relates to an air supply system failure determination method in a fuel cell apparatus used, for example, in a fuel cell vehicle.
2. Description of the Related Art
In a fuel cell mounted, for example, in a fuel cell vehicle, an anode is provided on one side of a solid polymer electrolyte membrane and a cathode is provided on the other side, a fuel gas (for example, hydrogen gas) is supplied to the anode, an oxidizing gas (for example, oxygen or air) is supplied to the cathode, and chemical energy from the oxidation-reduction reaction between these gases is extracted as direct electrical energy.
There is a fuel cell apparatus using this type of fuel cell that realizes early discovery of abnormalities by detecting the fluctuation in the composition of the reformed gas supplied to the fuel electrode of the fuel cell (refer to Citation 1, Japanese Unexamined Patent Application, First Publication No. Hei 6-260195).
However, in this fuel cell, when the air supply system fails, supplying air having a flow rate and pressure suitable for generation of electricity to the fuel cell becomes difficult, and thus carrying out appropriate detection of air supply system failure is very important in terms of maintaining the reliability of the fuel cell apparatus.
In consideration of the above-described problems, it is an object of the present invention to provide a fuel cell apparatus that can reliably detect the failure of the air supply system, and can maintain the reliability of the fuel cell apparatus.
In order to attain the object described above, according to the present invention, there is provided an oxidizing agent supply system failure determination method for a fuel cell for use with a fuel cell apparatus provided with a fuel cell that is supplied with a fuel and an oxidizing agent, and an oxidizing agent supply system that has an oxidizing agent condition adjusting means that adjusts condition of the oxidizing agent supplied to the fuel cell, comprising the step of: determining that the oxidizing agent supply system has failed if an absolute value of a difference between an actual value of a supply provided by the oxidizing agent condition adjusting means and a first predetermined value that is compared to the actual value is equal to or greater than a second predetermined value and a predetermined period of time has passed.
According to this invention, because the determination is carried out based on the fact that when the oxidizing agent supply system is normal, the absolute value of the difference between the actual value of the supply provided by the oxidizing agent condition adjusting means and the first predetermined value that is compared to the actual value is controlled within a predetermined time and within a predetermined value, it is possible to detect appropriately that there has been a failure in the oxidizing agent supply system, and thereby, it becomes possible to take appropriate measures that depend on the failure, and thereby maintaining the reliability of the fuel cell apparatus can be realized.
Preferably, the oxidizing agent condition adjusting means comprises a flow rate adjusting means that adjusts a flow rate of the oxidizing agent supplied to the fuel cell, and the actual value is an actual flow rate of the oxidizing agent which the flow rate adjustment means supplies and the first predetermined value is a command value sent to the flow rate adjusting means.
According to this invention, because the determination is carried out based on the fact that when the oxidizing agent supply system is normal, the absolute value of the difference between the actual flow rate of the oxidizing agent and the command value sent to the flow rate adjusting means is controlled within a predetermined time and a predetermined value, it is possible to determine properly the failure of the oxidizing agent supply system, and thereby, it becomes possible to take appropriate measures that depend on the failure, and thereby maintaining the reliability of the fuel cell apparatus can be realized.
Preferably, the oxidizing agent condition adjusting means comprises a pressure adjusting means that adjusts pressure of the oxidizing agent supplied to the fuel cell, and the actual value is an actual pressure of the oxidizing agent which the pressure adjusting means supplies and the first predetermined value is a command value sent to the pressure adjusting means.
According to this invention, because the determination is carried out based on the fact that when the oxidizing agent supply system is normal, the absolute value of the difference between the actual pressure of the oxidizing agent and the command value sent to the pressure adjusting means is controlled within a predetermined time and a predetermined value, it is possible to determine properly the failure of the oxidizing agent supply system, and thereby, it becomes possible to take appropriate measures that depend on the failure, and thereby maintaining the reliability of the fuel cell apparatus can be realized.
Preferably, the fuel cell apparatus further comprises a cooling system that cools the fuel cell, and the oxidizing agent condition adjusting means comprises a flow rate adjusting means that adjusts a flow rate of the oxidizing agent supplied to the fuel cell, and the actual value is an actual flow rate of the oxidizing agent which the flow rate adjusting means supplies and the first predetermined value is a pressure of a cooling medium supplied to the cooing system, and it is determined that the oxidizing agent supply system has failed if a state in which a generated current of the fuel cell is equal to or less than a predetermined value and the absolute value of a difference between the actual flow rate and a pressure of the cooling medium is equal to or greater than the second predetermined value has passed a predetermined period of time.
According to this invention, because the determination is carried out based on the fact that when the oxidizing agent supply system is normal, the state in which the generated current of the fuel cell is equal to or less than a predetermined value and the absolute value of the difference between the actual flow rate and the pressure of the cooling medium is equal to or greater than the second predetermined value is controlled within a predetermined time, it is possible to determine properly the failure of the oxidizing agent supply system, and thereby, it becomes possible to take appropriate measures that depend on the failure, and thereby maintaining the reliability of the fuel cell apparatus can be realized.
The above and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.